import type { FinancialCadence, FinancialStatementPeriod } from "@/lib/types";

export type FinancialHistoryWindow = 3 | 5 | 10;

export function financialHistoryLimit(
  cadence: FinancialCadence,
  window: FinancialHistoryWindow,
) {
  if (cadence === "quarterly") {
    return window * 4 + 4;
  }

  return window + 2;
}

function visiblePeriodCount(
  cadence: FinancialCadence,
  window: FinancialHistoryWindow,
) {
  if (cadence === "quarterly") {
    return window * 4;
  }

  return window;
}

export function filterPeriodsByHistoryWindow(
  periods: FinancialStatementPeriod[],
  cadence: FinancialCadence,
  window: FinancialHistoryWindow,
) {
  if (periods.length === 0) {
    return periods;
  }

  const count = visiblePeriodCount(cadence, window);
  if (periods.length <= count) {
    return periods;
  }

  return periods.slice(-count);
}